(REUTERS) - Holders Barcelona were knocked out of the Copa del Rey after suffering a 3-2 defeat in extra-time at Athletic Bilbao in the last 16 on Thursday (Jan 20) as their difficult season continued.

Bilbao dominated a thrilling match and went ahead early thanks to a beautiful cross-shot from Iker Muniain, who curled the ball past Marc-Andre ter Stegen into the top corner.

Former Manchester City forward Ferran Torres equalised for Barca with a brilliant right-footed strike from the edge of the area, his first goal for the club.

Inigo Martinez put Bilbao back in front after 86 minutes, winning a challenge against Gerard Pique to score, but Pedri netted a fine goal in stoppage time to send the game into extra-time.

Man of the Match Muniain scored the winner with a penalty after the video assistant referee spotted a handball from Jordi Alba inside the area.

Bilbao joined Real Madrid, Real Sociedad, Valencia, Real Betis, Rayo Vallecano, Mallorca and Cadiz in the quarter-finals.

The draw will take place on Friday.

Meanwhile, Barcelona's disappointing campaign continues.

Eliminated at the Champions League group stage, they lost to Bilbao in a repeat of last year's final, which they won 4-0, and two of their most promising players, Ansu Fati and Pedri, were substituted due to injury.

"We will see on Friday what they have but it is worrying how Ansu Fati left the game," Barcelona manager Xavi Hernandez told a news conference.

"We knew that it would be a tough game and I'm proud my players fought and gave their best. We still have La Liga and Europa League to fight for and we'll do it until the end."